Effects of coasting on the outcome of intracytoplasmic sperm injection-embryo transfer cycles

OBJECTIVES: To determine the effects of 'coasting' on the outcome of controlled ovarian hyperstimulation (COH) and intracytoplasmic sperm injection-embryo transfer (ICSI-ET). DESIGN: Retrospective study. SETTING: IVF Centre, Ozel Ege Tup Bebek Merkezi, Izmir, Turkey. SAMPLE: Twenty-six coasted and 52 non-coasted COH and ICSI-ET patients were enrolled in this retrospective study. METHODS: Coasted patients were enrolled consecutively during the study period, and two non-coasted controls were selected from our database for each coasted patient. Coasting was decided when serum oestradiol level was > or = 4000 pg/mL. Groups were compared using chi2 and Mann-Whitney U-tests for statistical analysis. MAIN OUTCOME MEASURES: Number of oocytes collected, metaphase II (MII) oocytes and cleaving embryos, the fertilisation rate and clinical pregnancy rate were the main outcome measures. RESULTS: Number of oocytes collected, number of MII oocytes, number of cleaving embryos, fertilisation rate and clinical pregnancy rate for the coasted and non-coasted groups were 15.5 +/- 5.2 and 14.0 +/- 7.1, 9.7 +/- 4.8 and 9.3 +/- 3.9, 6.8 +/- 3.9 and 5.8 +/- 3.1, 0.85 +/- 0.18 and 0.78 +/- 0.18, 13/26 and 24/52, respectively; these differences were not statistically significant. None of the patients in the coasted group were hospitalised for signs or findings of severe ovarian hyperstimulation syndrome. CONCLUSIONS: Coasting does not adversely affect the number and the function of mature oocytes and the clinical pregnancy rate.